1. Field of the Invention
The present invention relates to a method for preserving an adhesive tape and a method for preserving an article to which the same has been applied (hereinafter, referred to as "article using the same"), and more particularly to a method for preserving which comprises enclosing an adhesive tape (or an article using the same) together with an oxygen absorbent and a drying agent in a container having a gas barrier property and then sealing the container.
2. Prior Art
In adhesive tapes, adhesives including rubber adhesives, acrylic adhesives, vinylic adhesives, silicone adhesives etc., are used depending upon the characteristics of the adhesive. The adhesives applied to the tapes are degraded due to environmental causes such as oxygen, heat, light, ozone, moisture, etc. Thus, an unused roll-wound adhesive tape during storage or an adhesive tape attached to articles during use is degraded often causing various troubles.
In order to inhibit degradation of an adhesive tape, adhesives with degradation-inhibitor added are used. The degradation of an adhesive is mostly due to oxidation. It is known that as degradation-inhibitors, usually aldehydes, amines, phenols, etc., are suitable in the same manner as in rubber products. However, since most of them have contaminative property, uncontaminative substances need to be selected in a transparent or white tape. Furthermore, even when a degradation-inhibitor has been added, it is not always perfect. Also in an adhesive tape wherein a degradation-inhibitor has been added, when the adhesive tape or an article using the same was preserved for a long time or exposed to severe environments of high temperature and high humidity even for a short time, in some cases a release paper became difficult to peel off, and stringiness occurred and furthermore durability disappeared due to deterioration of adhesive force.
Although recently, processes using chip-form electronic parts attached to a carrier tape, to continuously mount the chip-form electronic parts on the surface of printed circuit boards while peeling them from the carrier tape by means of an automatic mounting machine have become common in the electronics industry, ageing of the carrier tape to which the chip-form electronic parts are attached has become problem. It is troublesome if the carrier tape on which chip-form electronic parts are loaded is degraded and its adhesion is reduced during transportation or storage, resulting in the release of the electronic parts from the carrier tape. It is also undesirable for peel strength to increase. Still more, when stringiness occurs, continuous mounting of electronic parts may be disturbed and products may be contaminated.
In order to inhibit degradation of an adhesive tape, drying agents including silica gel, etc., have been used for preservation of adhesive tape and an article using the same. When moisture was merely removed to provide dry atmosphere, the effects of preservation were insufficient because deterioration of function always occurred due to deterioration of adhesion. Thus, although application of a drying agent together with an oxygen absorbent has been attempted using, for example, already known oxygen absorbents containing metals and metal salts including, typically, iron powders and iron salts and organic compounds including, typically, catechol and ascorbic acid as the main ingredients, good preservation has not yet been secured. Thus, under the present situation, no simple and easy method for preserving an adhesive tape or an article using the same has yet been found.